PROJECT SUMMARY Infectious diseases account for one quarter of global deaths and massive economic loss. Pathogen discovery is critical in combating infectious diseases. However, the causative agents in a large percentage of clinical infectious disease cases remain unidentified. Often occurring in resource-limited areas, major outbreaks were caused by newly emerging viruses, mostly wildlife-originated. The pressing challenges in viral infectious diseases call for a sample-to-answer virus discovery platform that can prepare viral samples from environmental and clinical samples for high throughput sequencing based virus discovery. In this proposed research, we will develop a new carbon nanotube 3D sample preparation and enrichment microdevice (CNT- 3D-SPEM) that employs engineered carbon nanotube material, as shown in our preliminary study, into a new continuous flow microfluidic design for virus particle enrichment. The new microfluidic design has a unique self- regulating flow mechanism to achieve high virus capture efficiency and high sample capacity and flow rate simultaneously. After enrichment, the captured viruses are lyzed inside the CNT-3D-SPEM. The viral genome will be purified and amplified in situ, which are required sample preparation steps for virus discovery through high throughput sequencing. Working with co-investigators together, we will conduct multiple pilot studies that use the developed technology for virus discovery from clinical and environmental samples. The ultimate goal is to develop the entire high-performance portable platform to advance virus discovery for the battle with viral infectious diseases.